In the News

LSU VET MED PROFESSOR NAMED NEW DIRECTOR OF GRADUATE EDUCATION

Education

Post-doctoral Fellowship, Fondation pour la Recherche Medicale

Post-doctoral Fellowship, Institut National de la Recherche Agronomique

Post-doctoral Fellowship, European Molecular Biology Organization

PhD, Washington University, 2001

BS, University of Illinois, 1995

Research Interest

The Gram-negative α-proteobacteria of the genus Rickettsia are small (0.3-0.5 x 0.8-1.0 mm), obligate intracellular organisms.  They are categorized into two major groups, the Spotted Fever Group (SFG) and Typhus Group (TG), which can be distinguished by antigenicity and intracellular actin-based motility.  Members of this genus are responsible for severe human and animal diseases and have been considered emerging and re-emerging human pathogens.  Our laboratory is interested in further understanding the global mechanisms employed by rickettsial species to cause disease using several in vivo and in vitro models of pathogenesis.  Specifically, my laboratory is interested in i) elucidating the host cell pathways and bacterial factors that are involved in intracellular proliferation and survival of pathogenic Rickettsia species in mammalian target cells; ii) elucidating the function(s) of a cohort of Rickettsia proteins termed “effectors” that are secreted into the mammalian cell during infection and iii) determining how Rickettsia species infect and highjack cells in the blood circulation to disseminate within an infected mammal.  The overall goals of these studies are to further enhance our understanding of pathogen-host cell interactions and to utilize this information to develop more efficacious therapies against rickettsial diseases in human and companion animals. 

Teaching Interest

I am currently the course director of the didactic course VMED 5130 - BACTERIOLOGY AND MYCOLOGY which is a required course for 1st year veterinary students. I am also interested in promoting the teaching of mechanisms of bacterial pathogenesis to students at the graduate (Ph.D.) level. 

Awards & Honors

2018 and 2019, Dean's Teacher Merit Honor Roll

2017, Zoetis Award for Veterinary Research Excellence

2016, Elected Member, Tau Chapter of the Society of Phi Zeta

Publications

Fish, A.I., Riley, S.P., Singh, B., Riesbeck, K.,and Martinez, J.J., (2017). Elucidation of the biochemical interaction between Rickettsia conorii Adr1 and human host vitronectin.  Front. Cell. Infect. Microbiol.7:61. PMID:28299286

Garza, D.A., Riley, S.P., and Martinez, J.J., (2017).  Expression of Rickettsia Adr2 protein in E. coli is sufficient to promote resistance to complement-mediated killing, but not adherence to mammalian cells. PLoS One. 12(6):e0179544. doi: 10.1371/journal.pone.0179544. PMID:28662039

Riley, S.P., Pruneau, L., and Martinez, J.J., (2017).  Evaluation of changes to the Rickettsia rickettsii transcriptome during mammalian infection.  PLoS One 2017 Aug 23;12(8):e0182290. doi: 10.1371/journal.pone.0182290. PMID: 28832688

McClure EE, Chávez ASO, Shaw DK, Carlyon JA, Ganta RR, Noh SM, Wood DO, Bavoil PM, Brayton KA, Martinez J.J, McBride JW, Valdivia RH, Munderloh UG, Pedra JHF., (2017).  Engineering of obligate intracellular bacteria: progress, challenges and paradigms. Nat Rev Microbiol. 2017 Sep;15(9):544-558. doi: 10.1038/nrmicro.2017.59. Epub 2017 Jun 19. Review. PubMed PMID: 28626230; PMCID: PMC5557331

Riley, S.P., Fish, A.I., Del Piero, F., Martinez J.J,  (2018).  Immunity against the obligate intracellular pathogen Rickettsia australis requires a functional complement system.  Infect. Immun 86:e00139-18. https://doi.org/10.1128/IAI.00139-18

Curto P, Santa C, Allen P, Manadas B, Simões I, Martinez JJ., (2019). A Pathogen and a Non-pathogen Spotted Fever Group Rickettsia Trigger Differential Proteome Signatures in Macrophages. Front Cell Infect Microbiol. 2019;9:43. doi: 10.3389/fcimb.2019.00043. eCollection 2019. PubMed PMID: 30895174; PMCID: PMC6414445

Curto P, Riley SP, Simões I, Martinez JJ., (2019). Macrophages Infected by a Pathogen and a Non-pathogen Spotted Fever Group Rickettsia Reveal Differential Reprogramming Signatures Early in Infection. Front Cell Infect Microbiol. 2019;9:97. doi: 10.3389/fcimb.2019.00097. eCollection 2019. PubMed PMID: 31024862; PMCID: PMC6467950

Allen PE, Martinez JJ.(2020) Modulation of Host Lipid Pathways by Pathogenic Intracellular Bacteria. Pathogens. 2020 Jul 28;9(8). doi: 10.3390/pathogens9080614. Review. PubMed PMID: 32731350; PubMed Central PMCID: PMC7460438

Kristof MN, Allen PE, Yutzy LD, Thibodaux B, Paddock CD and Martinez JJ, (2021) Significant Growth by Rickettsia species within Human Macrophage-Like Cells is a Phenotype Correlated with the Ability to Cause Disease in Mammals. Pathogens 2021, 10(2), 228; https://doi.org/10.3390/pathogens10020228

Allen PE, Noland RC and Martinez JJ, (2021) Rickettsia conorii survival in THP-1 macrophages   involves host lipid droplet alterations and active rickettsial protein production.  Cell. Microbiol 2021 Aug 31;e13390.doi:10.1111/cmi.13390. Online ahead of print 

Grant Funding

LSU Vet Med Competitive Organized Research Program (CORP Funding mechanism), Martinez (PI) 08/1/21-07/30/22. Characterization of Rickettsia ankyrin rich repeat protein function in modulating host cell signaling pathways.

NIH/NIAID 1R21-AI111086 PI: J. Martinez  Title: “The retropepsin-like anzyme RC1339/APRick from Rickettsiae as a potential therapeutic target for rickettsial disease.”  Project Period: 05/01/15-04/30/17.  NCE to 4/30/2018. Total direct costs: $275,000

NIH/NIAID 2R01-AI072606-11 PI: J. Martinez. Title: “The roles of conserved outer-membrane proteins in SFG rickettsial pathogenesis.  Total direct costs: $1,250,000.  Annual salary recovery or effort: 10% Project Period: 03/02/09-01/31/20, NCE to 01/31/21

NIH/NIAID 2R01AI077784-06 PI: K. Macaluso; J.Martinez (co-investigator) Title: “Molecular basis for spotted fever group Rickettsia vector competence in ticks.” Project period: 08/25/2015-01/30/2020.

1P30GM110760-01 Kousoulas (Prog Dir); Martinez (Protein Core Director) 06/02/2014-04/30/2019, NCE to 01/01/2020, Center for Experimental Infection Disease Research (COBRE) Phase III.